Countdown to Christmas... An Advent Challenge

[Nick Mitchell]

11th December - Cylinders

 

There are still many details to make and fit to the loco body, but with the main superstructure complete, my thoughts turned to that lovely Walschaert's valve-gear. For many modellers it's the thing which puts them off LMS locos, but for me it is the main event.

 

Now, like many kits, this one has been designed to represent a locomotive in mid-gear. However, with a few little tweaks here and there, and the odd extra pivot joint, it is quite feasible to set the loco in forward or reverse gear.

 

Before anyone gets excited, I'm not talking about making the valve-gear actually reverse by itself - that would be completely crazy to attempt in 2mm scale... but the additional movement of the radius rod and the top of the combination lever when the loco is "in gear" add significantly to the authenticity of the model.

 

I always begin valve-gear construction with the cylinders and slide-bars. The basic cylinder block has a front and rear that fold up from a central spacer, and half-etched wrappers form the outer surface. The slide bars are laminated from two layers of etch, and plug into the cylinder rear faces.

 

 

As is my normal practice, I opened out the holes in the cylinder front and rear faces so that brass tubes could be inserted to support the piston rods. This adds greatly to the strength of the cylinder block during assembly.

 

The first modification to make more of the valve gear "work" is the addition of a second tube for the valve spindle, which will also slide in and out of the cylinder block. The valve spindle itself will be made from .45mm brass rod, which is a sliding fit in the tube. (This is actually the stuff sold by Model Signal Engineering as T132 "bearing tube", although on the Wizard Models website it is now listed as having nickel silver rod).

 

The piston rod tube protrudes about 1mm from the rear face of the cylinders to represent the gland, and the valve spindle tube about 1.5mm to support the valve chest ends:

 

 

And speaking of those valve chest ends, they were the next parts I turned on my lathe.

The ones for the front end of the cylinder block had a 0.45mm spigot turned on the rear faces, so they could be plugged into the tube for perfect alignment.

The ones for the rear end had a 0.9mm hole drilled so they could slip over the aforementioned tube.

 

 

One of the front covers being tested in position:

 

 

And here, the front and rear covers have been soldered in place.

 

 

I also soldered the front cylinder covers over the ends of the piston rod tubes.  These discs are included as an etched component in the kit.

 

 

With the cylinders and slide bars assembled, the next job was to test the fit of the pistons and crossheads. There are various options for these, including castings, but in this kit, Nigel has included some components to fabricate a crosshead. I found this method of construction works a treat.

 

There is a front and rear face, and a central piece which folds into a U shape. The legs of the U form the two sliding faces of the crosshead, and the base of the U is a mounting platform for the piston rod. Small tabs on the legs of the U engage in slots in the front and rear face pieces, ensuring everything can only go together square and in perfect alignment.

 

The piston rod is just a plated steel dressmakers pin, cut to length and rounded off, with the head filed flat and square to fit onto the crosshead.

 

 

A certain amount of fettling is always required, but the goal is for the crosshead to slide freely in the slidebars such that when they are held vertically, it will fall under its own weight without sticking.

 

[VRBroadgauge]

5 hours ago, Nick Mitchell said:

11th December - Cylinders

 

There are still many details to make and fit to the loco body, but with the main superstructure complete, my thoughts turned to that lovely Walschaert's valve-gear. For many modellers it's the thing which puts them off LMS locos, but for me it is the main event.

 

Now, like many kits, this one has been designed to represent a locomotive in mid-gear. However, with a few little tweaks here and there, and the odd extra pivot joint, it is quite feasible to set the loco in forward or reverse gear.

 

Before anyone gets excited, I'm not talking about making the valve-gear actually reverse by itself - that would be completely crazy to attempt in 2mm scale... but the additional movement of the radius rod and the top of the combination lever when the loco is "in gear" add significantly to the authenticity of the model.

 

I always begin valve-gear construction with the cylinders and slide-bars. The basic cylinder block has a front and rear that fold up from a central spacer, and half-etched wrappers form the outer surface. The slide bars are laminated from two layers of etch, and plug into the cylinder rear faces.

 

 

As is my normal practice, I opened out the holes in the cylinder front and rear faces so that brass tubes could be inserted to support the piston rods. This adds greatly to the strength of the cylinder block during assembly.

 

The first modification to make more of the valve gear "work" is the addition of a second tube for the valve spindle, which will also slide in and out of the cylinder block. The valve spindle itself will be made from .45mm brass rod, which is a sliding fit in the tube. (This is actually the stuff sold by Model Signal Engineering as T132 "bearing tube", although on the Wizard Models website it is now listed as having nickel silver rod).

 

The piston rod tube protrudes about 1mm from the rear face of the cylinders to represent the gland, and the valve spindle tube about 1.5mm to support the valve chest ends:

 

 

And speaking of those valve chest ends, they were the next parts I turned on my lathe.

The ones for the front end of the cylinder block had a 0.45mm spigot turned on the rear faces, so they could be plugged into the tube for perfect alignment.

The ones for the rear end had a 0.9mm hole drilled so they could slip over the aforementioned tube.

 

 

One of the front covers being tested in position:

 

 

And here, the front and rear covers have been soldered in place.

 

 

I also soldered the front cylinder covers over the ends of the piston rod tubes.  These discs are included as an etched component in the kit.

 

 

With the cylinders and slide bars assembled, the next job was to test the fit of the pistons and crossheads. There are various options for these, including castings, but in this kit, Nigel has included some components to fabricate a crosshead. I found this method of construction works a treat.

 

There is a front and rear face, and a central piece which folds into a U shape. The legs of the U form the two sliding faces of the crosshead, and the base of the U is a mounting platform for the piston rod. Small tabs on the legs of the U engage in slots in the front and rear face pieces, ensuring everything can only go together square and in perfect alignment.

 

The piston rod is just a plated steel dressmakers pin, cut to length and rounded off, with the head filed flat and square to fit onto the crosshead.

 

 

A certain amount of fettling is always required, but the goal is for the crosshead to slide freely in the slidebars such that when they are held vertically, it will fall under its own weight without sticking.

 

Nick, you don't happen to have a picture of the crosshead components before you soddered them together? I'm interested in how that works.

[Klaus ojo]

Hi,

will this help?

The 2 strips with the tabs on both sides have to be folded in an U-shape at the half etched lines. There are possibly 2 kinds of crosshead layers on the etch (for the 7F there were 2), a pair with slot and one without slots. The slots are for the tabs on both sides of the U. They may need some widening and the tabs some filing to be a perfect fit. On the first I´ve soldered together I put too much pressure and it collapsed. It was some effort to rework it but it went well in the end. I like this crosshead design...

cheers

Klaus

crosshead parts from Nigel Hunt SDJR 7F etch.pdf

Edited December 11, 2022 by Klaus ojo
a bit more text...

[Nick Mitchell]

Thanks for posting this, Klaus.

The arrangement on the 2-6-4T is identical.

 

4 hours ago, Klaus ojo said:

There are possibly 2 kinds of crosshead layers on the etch (for the 7F there were 2), a pair with slot and one without slots.

The pair without slots are in case you want to use a cast part for the centre/rear section of the crosshead (which Nigel has also made available - I believe to replace the old "crosshead strip" that has been unavailable for about 20 years).

 

[65179]

29 minutes ago, Nick Mitchell said:

Thanks for posting this, Klaus.

The arrangement on the 2-6-4T is identical.

 

The pair without slots are in case you want to use a cast part for the centre/rear section of the crosshead (which Nigel has also made available - I believe to replace the old "crosshead strip" that has been unavailable for about 20 years).

 

Crosshead strip and cast crossheads both now available from N Brass

 

https://www.nbrasslocos.co.uk/fitall.html#ROD

 

Simon 

Edited December 11, 2022 by 65179

[VRBroadgauge]

Much appreciated for the information.

Another question. So the piston rod has an end squared off and is soldered to the center part of the U? I take it that this is lined up by eye and there are no guides on the etch. Is that joint a problem or is it strong enough for future use? I'm just thinking of the design process and trying to make it easy for myself as regards to construction.

[Nick Mitchell]

31 minutes ago, VRBroadgauge said:

Much appreciated for the information.

Another question. So the piston rod has an end squared off and is soldered to the center part of the U? I take it that this is lined up by eye and there are no guides on the etch. Is that joint a problem or is it strong enough for future use? I'm just thinking of the design process and trying to make it easy for myself as regards to construction.

Basically yes, yes and yes.

The head of the pin is filed flat. You have to remove the plating otherwise it won't take solder.

With this design, the front and rear pieces have an extension which the pinhead fits in-between. SO with careful filing, part of the alignment issue is taken care of.

That just leaves the vertical alignment to take care of. If you find a way of holding the pin securely while you offer up and solder on the crosshead, you can do it by eye.

You could hold the pin in the cylinders, and the crosshead in the slide bars to establish alignment, but I wouldn't want to risk using them as a soldering jig for fear of accidentally soldering the crosshead to the slide bars.

[Nick Mitchell]

12th December - Modified valve-gear parts

 

Seen below are the etched combination levers. The top is to the right of the picture.

Nigel, it seems, had the incredible foresight to put two holes in the top end of these parts, as if he knew what I had in mind...

 

 

These bits, and the union links, are rather on the chunky side.

Actually, this is a smart design move when it comes to etching, as chunky parts can be slimmed down far more easily than over-etched parts (which sometimes do happen) can be beefed up.

A case in point - I was building a Stephen Harris wagon kit on the Association Roadshow stand at Manchester yesterday, and he provided 3 "chunkinesses" of hand-wheels to mitigate the vagaries of the etching process... a handwheel being much more tricky to slim down than a combination lever.

 

Anyway, the photo below compares the combination levers and union links before and after receiving the treatment...

 

 

The combination lever is slimmed to about 0.3mm. Fortunately my watchmaker's vice is able to grip the tiny edges, so by inserting .3mm rods in the holes to adjust the height of the part in the vice, I used a piece of nickel silver as a guide to file down to.

 

 

Turning next to the radius rods, these needed more drastic modification.

 

As supplied, there is a fold-up representation of the valve-spindle guide attached to the front end, but these needed to be removed since the radius rod is no longer going to be static.

The plan is to have valve spindle guides attached to the loco body, dangling from behind the valances.

Also, at the rear end, the long slots (where the lifting arm would connect) need to be made functional.

 

In the picture below, I've attacked the dimple in the upper rod and started opening the a hole to the diameter of the slot width - as a precursor to cutting out the webs and filing it smooth.

 

 

And here are the finished articles:

 

 

Next come the expansion links. The upper hole is the pivot point of the expansion link.

In mid-gear, the radius rods pass through the same point, and everything can be pivoted together as intended by the kit design.

For forward gear, the radius rods are lowered in the expansion links, so a new pivot joint needed to be drilled. The position of this will "fix" the gear.

 

 

I mentioned beefing up parts earlier, and I decided to add an extra half-etch thickness to the expansion links.

I did this in such a way as to suggest the bottom extensions (which will join to the eccentric rods) appear set back as in real life.

 

I soldered the two existing parts to a piece of 5 thou shim, as seen below, and then drilled through the holes before cuting them out.

 

 

Here are the parts I've prepared so far for the left hand valve-gear, laid out roughly as they will be joined together, along with the crosshead/piston.

 

Edited December 12, 2022 by Nick Mitchell

[queensquare]

1 hour ago, Nick Mitchell said:

12th December - Modified valve-gear parts

 

Seen below are the etched combination levers. The top is to the right of the picture.

Nigel, it seems, had the incredible foresight to put two holes in the top end of these parts, as if he knew what I had in mind...

 

 

These bits, and the union links, are rather on the chunky side.

Actually, this is a smart design move when it comes to etching, as chunky parts can be slimmed down far more easily than over-etched parts (which sometimes do happen) can be beefed up.

A case in point - I was building a Stephen Harris wagon kit on the Association Roadshow stand at Manchester yesterday, and he provided 3 "chunkinesses" of hand-wheels to mitigate the vagaries of the etching process... a handwheel being much more tricky to slim down than a combination lever.

 

Anyway, the photo below compares the combination levers and union links before and after receiving the treatment...

 

 

The combination lever is slimmed to about 0.3mm. Fortunately my watchmaker's vice is able to grip the tiny edges, so by inserting .3mm rods in the holes to adjust the height of the part in the vice, I used a piece of nickel silver as a guide to file down to.

 

 

Turning next to the radius rods, these needed more drastic modification.

 

As supplied, there is a fold-up representation of the valve-spindle guide attached to the front end, but these needed to be removed since the radius rod is no longer going to be static.

The plan is to have valve spindle guides attached to the loco body, dangling from behind the valances.

Also, at the rear end, the long slots (where the lifting arm would connect) need to be made functional.

 

In the picture below, I've attacked the dimple in the upper rod and started opening the a hole to the diameter of the slot width - as a precursor to cutting out the webs and filing it smooth.

 

 

And here are the finished articles:

 

 

Next come the expansion links. The upper hole is the pivot point of the expansion link.

In mid-gear, the radius rods pass through the same point, and everything can be pivoted together as intended by the kit design.

For forward gear, the radius rods are lowered in the expansion links, so a new pivot joint needed to be drilled. The position of this will "fix" the gear.

 

 

I mentioned beefing up parts earlier, and I decided to add an extra half-etch thickness to the expansion links.

I did this in such a way as to suggest the bottom extensions (which will join to the eccentric rods) appear set back as in real life.

 

I soldered the two existing parts to a piece of 5 thou shim, as seen below, and then drilled through the holes before cuting them out.

 

 

Here are the parts I've prepared so far for the left hand valve-gear, laid out roughly as they will be joined together, along with the crosshead/piston.

 

Excellent work Nick, this is where you leave blacksmiths like me behind. Superb stuff,

 

Jerry

[Gareth Collier]

On 11/12/2022 at 00:02, Nick Mitchell said:

11th December - Cylinders

 

Before anyone gets excited, I'm not talking about making the valve-gear actually reverse by itself - that would be completely crazy to attempt in 2mm scale... but the additional movement of the radius rod and the top of the combination lever when the loco is "in gear" add significantly to the authenticity of the model.

 

At about 34 seconds the craziness starts 😉

 

Edited December 12, 2022 by Gareth Collier

[Nick Mitchell]

13th December - Starting to assemble the valve gear

 

I mentioned previously that the valve spindle would be made from 0.45mm brass rod.

 

A short section at one end of the rod was squashed in my vice, and a small washer (with a 0.3mm hole) soldered onto the flat end. The washer could then be used as a jig to drill a hole through the brass. Below you can see the brass rod and washer ready to be fitted:

 

 

The valve spindle and radius rod pivot from pins inserted into the adjacent holes at the top of the combination lever.

The procedure to make the pivot joints is the same as any valve gear pivot - making a multi-layer sandwich with oiled cigarette paper - but two at once.

 

The two pivot wires were soldered to the combination lever first, then the long ends protruding from the front could be held in the vice while the sandwich was built up on the rear:

 

 

The "washer" being soldered on the rear in the picture above is a special double washer, made using the combination lever itself as a drilling template.

 

Here's another view, with the crosshead also attached:

 

 

The connecting rod is joined to the crosshead next, using a flanged crankpin with a turned-down flange as the pivot at the little end. I made an attempt to file a hexagon on the visible  protruding stub of the crankpin (using the dividing head on my lathe) but it can't really be seen in the pictures.

 

When all the the wires are trimmed and everything cleaned up, the first sub-assembly of the valve gear looks like this:

 

 

At each stage, I was constantly testing that everything pivoted and slid freely as it should.

 

The photo below was taken slightly earlier (before I fitted the valve chest end covers), while testing that the piston and valve spindle slid freely, and also (very importantly!) that the crosshead could pass behind the combination lever without catching.

 

 

Some people (Graham Farish included) put double bends into the combination levers to crank them out round crossheads etc. but I usually find this is not necessary.

 

There's not much clearance, as can be seen in the photo below - especially if the slidebars have been set outside the cylinder centre line - a common ruse to make room for the wheels to have some side play. But on the real thing, you often can't even fit your finger between the moving parts.

 

The view below looking along the slide bars shows there is just enough clearance. I filed a chamfer on the front end of the cross heads just in case, however...

 

 

To complete this sub-assembly, I had earlier added the expansion link and eccentric rod to the chain of parts, but this wasn't the smartest move, as it made threading it onto the motion bracket impossible, so I ended up having to take them off again! Still, they look nice in this photo:

 

 

With the left side largely complete, here are all the parts laid out ready to build the right side valve-gear.

 

 

Edited December 13, 2022 by Nick Mitchell

[Night Train]

Superb work. I usually make a pigs ear trying to solder O gauge kits. Doing that in 2mm is far beyond my talent level. Its a delight to see it come together.

[Nick Mitchell]

14th December - Completing the valve gear assembly

 

I mentioned yesterday that I needed to separate the chain of valve-gear parts in order to thread the radius rod through the motion bracket.

There was some preparation to do to the motion bracket before this could happen - soldering a flange round the edges of the bracket, and installing pivot rods in the expansion link support brackets.

 

In the picture below you can see the prepared motion bracket, with the right hand radius rod threaded through, and the two parts of the valve gear finally joined together.

Eventually, the two ends of this "chain" of 8 parts (not counting the valve spindle, which dangles off the side) will join back together on the driven wheel's crankpin.

 

 

Where I've joined the expansion link to the eccentric rod, I needed to file the front of the joint flush. Obviously, this would file all the solder away, so before soldering I countersank the hole in the expansion link slightly. This allowed a ring of solder to remain in the countersink.

 

The next stage was to "hang" the rods off the motion bracket by the expansion link.

In the photo below, the right hand side has been done, and the left hand side is about to be soldered. The extension of the 0.3mm pivot rod is inserted into a hole in my work board, and is holding the whole assembly in place for soldering. The usual cigarette paper sandwich is in place, with the etched securing washer on top.

 

 

With the soldering complete and everything cleaned up, the assembly takes on the general appearance of a metallic drunken daddy longlegs, and is quite delicate...

 

 

The next stage was to slide the piston and valve rods into the cylinder block, and using the loco chassis as a jig to hold the parts in alignment, solder the slide bars to the motion bracket.

This traps the crossheads on the slide bars, and completes the "engine unit" as a demountable sub-assembly.

 

 

Some people like to leave the engine unit demountable like this, but it the two halves need to be electrically isolated which could be achieved in various ways.

 

The way I do things now, however, is to solder the unit to the frames and simply saw through it. I know that this means if I ever need to remove the wheels from the chassis, I have made life very difficult for myself, but my logic is that if I ever need to remove the wheels from the locomotive, I'll be in the territory of a full chassis re-build anyway. I don't envisage my locos running in an environment like Copenhagen Fields, and if I maintain the current rate of progress on my layout, removing the wheels from the frames to replace worn-out axles will be somebody else's problem long after I'm dead!

 

Here is the end result after soldering and gapping (with a piercing saw for the cylinder block, which could be threaded through the chassis). The gap in the motion bracket was chapped out with etch scissors. In this view I've also soldered in and gapped the weigh shaft.

 

 

I still need to fix the lifting arms to the weigh shaft. These won't be functional, as the radius rod is self supporting. But they are for another day.

 

 

Obviously(?) everything was thoroughly tested for clearances and smooth movement before the cylinders and motion bracket were soldered in place, and the return cranks soldered to the crank pins and the latter trimmed to length.

Only at this point could the chassis with the valve gear be properly assessed for smooth running. Fortunately, everything seemed to be okay...

 

[Nick Mitchell]

15th December - Cylinder valves and drains

 

The valves on the bottom of the cylinders are quite distinctive on these Fowler tank engines. Distinctively chunky.

Nigel has included some parts on the etch to represent these, with two layers to build up the details, including the drains.

 

 

Flat etches to represent round things aren't always fully satisfying, so I decided not to use these components, and to see if I could make something that was more round and chunky.

 

To be fair, on most photos, these bits are hidden away in shadow, so having something down there that is roughly the right shape to suggest their presence is a valuable short-cut if that is your inclination - and with the bits included the builder has that choice.

 

I turned a batch of valves on my lathe, incorporating a short spigot - the idea being that I could mark and drill holes in the cylinders and then "plug" them in.

Here are two of the initial turnings. The spigots are to the top left of the picture. The bottom of the valves (bottom left of picture) need to be tapered, but not yet...

 

 

There's a bar that passes down the middle of these round things, so I sawed a 0.2mm slot (using a piercing saw) through the spigot and into the bodies.

In the picture below, I'm holding the valve in a watchmaker's lathe collet (hence not having tapered the bottom of the valve), mounted in a collet holder.

 

 

Here are two of the four slotted valves, after being put back in the lathe and having the tapers turned:

 

 

I drilled two holes at the correct spacing in my work board to mount the valves, and soldered a thin strip of brass (scrap etch saved up from the fret of another kit) into the slots.

In the picture below you can see a brass shim being used to pack the strip to the correct height.

 

 

And here is the the first pair of valves when removed from the holes:

 

 

 

 

 

The drains came next, and here I used the etching as a template to get the shape and spacing of the individual pipes right.

The drains are made from strands of 0.2mm copper wire.

I stuck the three individual wires to a piece of paper with Pritt Stick to hold them in place relative to each other, then soldered them together before trimming them to length.

These assemblies were then carefully soldered to the back of the bars between the valves.

 

 

Originally these cylinder drain pipes were quite long, and were fixed to the back of the front footsteps. After the war, they were cut back, which is fortunate, as the long versions may well have interfered with the swing of the front pony truck.

 

[Nick Mitchell]

16th December - Chassis finishing(?) touches

 

The last little bits of the valve-gear are the lifting links.

There were representations of these in the kit, but they weren't really suitable for the way I wanted to use them. Rather than have a folded L shape, I wanted to gave a separate link attached to the weigh shaft I'd preciously fitted.

 

The arms were formed from scrap etch - I never throw old kit frets away. I found strips of a suitable width, and drilled hoes of 0.3mm at one end, and 0.5mm at the other end.

Somehow I managed to solder a 0.3mm rod through the slot in the end of the radius rod without locking everything up solid.

 

Here is the end result from a couple of different angles:

 

 

 

The bogie and pony truck had already been assembled when I but the main frames together, but i still needed to fit them.

 

Having fitted a pivot pin for the pony truck, I decided to beef up the pivot arm with the addition of a brass washer.

 

 

As can be seen below, the pony truck is constructed along the same lines as the main frames, with the centre section electrically isolated.

 

 

The rear bogie is similar:

 

 

Below are the components for mounting the bogie and pony truck.

The pivot on the left is a spare one I turned at the same time, but illustrates the concept. A 14BA nut will be soldered in the up on the top. Nigel sells cast versions of these.

The short screw on the right secures the bony truck. The longer screw and the spring are for the bogie.

 

 

The photo below attempts to illustrate how the spring fits over the pivot and the bolt up through the middle of it. The bearing attached to the spring engages in the slot in the bogie stretcher.

 

 

Viewed from underneath, before the retaining bolt is fitted, the spring bearing can be seen in the bogie stretcher slot in the picture below, allowing the bogie to both rotate and slide sideways.

 

 

With the motor bolted into place, the chassis is more or less compete and ready for testing.

 

 

I'm thinking about fitting some form of centre springing to the pony truck, and DCC will eventually be fitted. I also need to think about fitting functional couplings, but for now I will put the chassis to one side and move on to detailing the body.

[Simon D.]

Do you have a source for the small springs please?

 

Extraordinary stuff

Edited December 16, 2022 by Simon D.

[Izzy]

Beautiful work Nick. Could quite easily be taken for 7mm. A real masterclass. Thanks for showing it.

 

Bob

[Nick Mitchell]

2 hours ago, Simon D. said:

Do you have a source for the small springs please?

 

Extraordinary stuff

 

Hi Simon,

The ones I use are re-cycled from old-style n-gauge coupling springs.

 

You can buy these as spares from a couple of places:

https://www.farishnspares.co.uk/graham-farish/coupling-springs-gf0003-2.html

https://www.petersspares.com/peters-spares-ps12-replacement-graham-farish-brush-coupling-springs-pk10-n-gauge.ir

[Nick Mitchell]

17th December - Pipes, steps, roof, tank stays

 

I've now reached the point of working my way through long lists of fiddly details to add to the locomotive.

 

Quite a lot of work has gone into the details which have been added in the two photos below.

 

Firstly, the outside steam pipes were fitted. These permanently join the smokebox to it's saddle, so the fixing bolt (which would prevent the body fitting onto the chassis) can be dispensed with. The pipes were formed from lengths of nickel silver rod of appropriate diameter. The bottom end of the rod can be seen digging into my finger, it having been sawn off under the valance. Later I will grind it flush with the underneath of the running plate using a small grinding wheel in my mini-drill.

 

Secondly, the front footsteps have been fitted. The individual treads and the backing plates are provided as etched components as part of the kit.

 

Lastly, the grab handles on top of the steps were added. These have been bent up from 0.25mm nickel silver wire, and soldered from underneath.

 

 

 

I try to leave steps until late in the build process as they are quite vulnerable to being bent.

After the front ones were added, more appeared under the cab doorways.

I'm not sure why the ones under the bunker were added so much earlier... but they have survived unscathed thus far.

 

 

Next I turned my attention to the cab roof. This is one of the reasons I've taken so long to get round to completing this loco. Not because it was particularly challenging, but because I managed to loose it down behind a bookcase, which was in the middle of a run of Ikea "Billy" bookcases joined to each other and also to the wall. It took a long time to summon the willpower to empty the shelves and take everything apart to retrieve the offending article, but here it is, bent to shape (using my swage block again) as close to the profile of the cab front/back as I could get it.

 

 

I had toyed with the idea of making the cab roof removable, but in the end, decided to solder it in place at this stage - if nothing else to stop it from getting lost again!

 

 I'd previously soldered some scrap etch under the cab sides to support the edges of the roof. The underside of the roof was tinned round the four edges, and then it was sweated into place. There was a slight overhang at both front and rear, and these were gently filed flush with the bent-over cab sides.

 

 

The ventilator "lid" is made from two layers of etch soldered together, with the edges rounded off. Sitting on the half-etched ribs on the roof gives a pleasing "raised" appearance.

 

 

Rain strips were included on the fret, and once soldered in place these disguise the join between the sides and roof.

 

 

Now that the boiler was permanently fixed in place, it was possible to fit the side-tank "stays", which join the tank to the boiler.

There are three each side, fitting onto the previously installed wires and base-plates on the tank tops.

 

 

 

 

 

[Nick Mitchell]

18th December - Chimney and Dome

 

The dome has an interesting story, but I can't tell you most of it!

At one point, I was planning to use an N Brass cast dome that I'd removed from a long-abandoned project to convert a Poole-made Farish Jinty.

But then I found a similar-looking dome that was mounted on a length of 1.5mm steel.

For the life of me, I can't remember where it came from or what it was originally for, but it looked Fowler-ish, and the curve of the base was just the right diameter for the boiler of the 2-6-4T. There were problems with the casting, so I decided to use this mystery dome instead.

I measured it, and found it to be too fat and too tall, so I put it in the lathe and turned it down to the correct dimensions.

A bit of work with a round file to tidy up the flare had it fit for purpose.

 

 

The photo below aims to give a sense of scale...

 

 

Despite it's forgotten provenance, it provided a useful short-cut.

The picture below shows it placed on the boiler, not yet permanently fixed.

 

 

The chimney, on the other hand, was made entirely from scratch.

 

I started by cutting a length of 4mm dia. brass rod, and facing it off to the correct length in the lathe.

I then filed the curve to fit on the smokebox.

Once I was satisfied with this, I put it back in the lathe and centre-drilled a hole to mount it on a length of 1.5mm axle steel.

 

The photo below shows the chimney "blank" fitted to its steel rod, test-fitted to the loco.

The loco is standing on the dimensioned drawing I made ready for turning the shape of the chimney...

 

 

I turned the shape of the chimney (according to the drawing) in the lathe, and drilled out the middle as far as I dared.

The result is shown below. The flare at the bottom will need to be finished off by filing...

 

 

...and after a few minutes with the file, the flare was formed, and the finished chimney could be returned to the lathe to have the steel rod parted off to form a short mounting spigot:

 

 

The chimney test-fitted on the loco (with the smokebox door again temporarily fitted to assess the "character" of the front end):

 

 

Sometimes I use epoxy to fix boiler furniture in place, but this time I decided to use solder.

When I'd fitted the chimney blank to the steel rod, I'd originally used Loctite to fix it, but unusually it came loose when I was doing the subsequent turning operations.

Rather than re-gluing, I soldered the rod back in place, which had resulted in the base of the chimney being tinned, with a fillet of solder round the rod.

When it came to fixing the chimney in place, It was easy enough to flux the smokebox top and apply heat to the chimney. It just melted itself in place,

Having soldered the chimney, I did the same with the dome.

 

These last few pictures show the results in cruel close-up.

 

 

 

 

 

 

[65179]

I think cruel close ups are for other people Nick.  Your work as usual bares scrutiny at any distance. The face has none of the usual 2mm/N giveaways to allow you to determine what scale it is.

Top notch stuff.

 

Simon

[Nick Mitchell]

19th December - More turned fittings

 

1. Safety valves

The bottom 3" of the safety valves have a round cover, which is provided for in the kit as two etched layers. These were soldered together, and the top edge rounded off.

 

I turned the visible parts of the safety valves (dialling the dimensions in on the top-slide I have for my lathe, so that I could get two identical parts) such that they plugged in to the holes provided in the etched base/cover. The plugs were left slightly long, so they protruded below the base.

 

 

The firebox wrapper has a hole to locate the centre of the safety valve base/cover.

I marked and drilled 2 additional holes for the actual valves, so as to provide a positive location for the protruding valves on their base.

 

 

Below are the valves finally soldered in place, with some cleaning up still to do.

 

 

2. Whistle

The whistle is another turning, and was quite a bit more difficult than the safety valves, being on a long stem with a valve lower down the stem.

The dimensions of the whistle itself are correct, but the lower part is a bit impressionistic. I think it looks okay.

 

 

3. Tank vents

The Fowler tanks had 3 styles of mushroom vents on the side tanks over their lives. Short ones, tall straight ones, and tall cranked-in ones.

For a post-war model, tall vents are the order of the day. The change-over from straight to cranked-in vents (to aid forward visibility) took place over a lengthy period either side of nationalisation. Having studied lots of photographs from around this time, I decided to go with straight vents.

 

Again, these were turned so that they could be plugged into the etched bases already installed on the tank tops.

 

 

 

 

Originally, the bunker tank had also had been fitted with cast mushroom vents, but breakages and blockages from being buried under coal on a daily basis led to their replacement with tall vent pipes, the open ends of which were tucked under the cab roof overhang to prevent the ingress of coal.

 

Representations of these pipes were bent up from brass rod, and soldered to the cab back.

 

 

[Nick Mitchell]

20th December - Insanity Bites ( = Mechanical lubricators)

 

Cast brass mechanical lubricators can be bought from N Brass in various styles. So of course I decided to make my own.

 

Perhaps this isn't as crazy as it sounds. Okay, it is as crazy as it sounds. BUT my justification is that the Fowler tanks lubricators sat on little pedestals rather than being directly fitted to the footplate. Because the lubricators are in a prominent position, I wanted the oil delivery pipes to be a feature too, and they sweep backwards from the lubricator itself. All in all, it seemed it would be "easier" to make them myself.

 

I started with the basic shape of the lubricator body. In an attempt to get two the same, I filed an approximation to the cross-section of the casing from a length of brass strip, and then sawed off two pieces the correct length.

 

These were then soldered to two "pedestals" cut from another piece of brass strip with the correct cross-section.

 

 

The pedestal was created with a lip around the bottom on three sides.

 

Fortune smiled on me at this point, as included on the etch for the loco were some small discs with a hole in the centre. There were actually spares of the bases for the stays that join the boiler to the side tanks. But they were perfect for soldering to the front of the lubricator bodies.

The hole in the middle of the disc, once soldered in place, acted as a guide for drilling a 0.3mm hole into the lubricator.

The hole was for a 0.3mm wire, on which was mounted an etched handrail knob, designed to represent the operating arm of the lubricator.

 

The photo below shows the stages of fixing the disc, then the arm:

 

 

After soldering, the protruding rod was filed flush, and the sides of the handrail knob filed back so that nobody would know I'd not just soldered a strip of nickel silver onto the front of the disc. Maybe I should have just done that!?!

 

 

The next stage was to saw a slot in the back of the lubricator body. I made the slots as deep as I dared, without risking the whole thing collapsing.

 

 

The idea behind the slots was to be able to thread a bunch of oil delivery pipes into them.

The pipes are made from 36swg (0.2mm) copper wire.

 

To hold everything in place for soldering, and make sure the pipes exited the lubricator in line and at a right angle, I cut long lengths of wire, and glued them all to a piece of paper using Pritt stick.

With plenty of flux, solder was introduced to the back of the slot, which wicked inside and fixed the wires:

 

 

Here is the first "piped up" lubricator from the visible side, balanced on the end of my finger:

 

 

When it came to fitting the lubricators to the footplate, I was concerned about them moving about and potentially falling apart.

In the end I decided to peg them in place.

This involved drilling a hole in the centre of the lubricator's pedestal from underneath, and soldering in a short length of nickel silver rod.

Holes could then be marked and drilled in the footplate to accurately position the lubricators.

I trimmed and bent the feed pipes to shape before fitting the lubricators.

Then it was easy to hold them securely in the correct position on the footplate, and solder them from underneath.

With flux between the lubricator and footplate, and solder introduced to the peg below the footplate, if enough heat is introduced (I used the big tip on my soldering iron) the solder gets drawn up into the joint, and a really neat joint can be made without needing to clean up on top.

The protruding rod and any excess solder was subsequently filed away under the footplate.

 

 

 

 

[Nick Mitchell]

Apologies to those who are waiting impatiently to open today's "window". I wasn't organised enough to write it last night, so it will have to wait until I've finished playing with the big train set this evening...

 

[Sithlord75]

Is that one which was needing work when I was there Nick?  And when are you planning on modelling it?  Lent?